8(s)hepe

8(S)-HEPE is a monohydroxy fatty acid produced by lipoxygenase oxidation of EPA. It acts to promote hatching of barnacle eggs at 10 nM, although it is not clearly identified as the natural egg hatching factor.

Resolvin E2 (RvE2) is a member of the specialized pro-resolving mediator (SPM) family of bioactive lipids.1It is produced from eicosapentaenoic acidviaan 18-HEPE intermediate, which is formed by aspirin-acetylated COX-2-mediated oxidation of EPA, by 5-lipoxygenase (5-LO) in human polymorphonuclear (PMN) neutrophils.2,3RvE2 (20 ng/animal) inhibits increases in inflammatory exudate neutrophil infiltration in a mouse model of peritonitis induced by zymosan A .3Hepatic RvE2 levels are increased in mice fed normal chow, as well as in a mouse model of high-fat diet-induced non-alcoholic fatty liver disease (NAFLD), by dietary supplementation with EPA.4Plasma levels of RvE2 are increased by dietary supplementation with fish oil containing ω-3 polyunsaturated fatty acids (PUFAs) in patients with peripheral artery disease or chronic kidney disease.1,5,6 1.Chiang, N., and Serhan, C.N.Specialized pro-resolving mediator network: An update on production and actionsEssays Biochem.64(3)443-462(2020) 2.Tjonahen, E., Oh, S.F., Siegelman, J., et al.Resolvin E2: Identification and anti-inflammatory actions: Pivotal role of human 5-lipoxygenase in resolvin E series biosynthesisChemistry & Biology131193-1202(2006) 3.Sungwhan, F.O., Pillai, P.S., Recchiuti, A., et al.Pro-resolving actions and stereoselective biosynthesis of 18S E-series resolvins in human leukocytes and murine inflammationJ. Clin. Invest.121(2)569-581(2011) 4.Echeverría, F., Valenzuela, R., Espinosa, A., et al.Reduction of high-fat diet-induced liver proinflammatory state by eicosapentaenoic acid plus hydroxytyrosol supplementation: Involvement of resolvins RvE1/2 and RvD1/2J. Nutr. Biochem.6335-43(2019) 5.Ramirez, J.L., Gasper, W.J., Khetani, S.A., et al.Fish oil increases specialized pro-resolving lipid mediators in PAD (the OMEGA-PAD II trial)J. Surg. Res.238164-174(2019) 6.Barden, A.E., Shinde, S., Burke, V., et al.The effect of n-3 fatty acids and coenzyme Q10 supplementation on neutrophil leukotrienes, mediators of inflammation resolution and myeloperoxidase in chronic kidney diseaseProstaglandins Other Lipid Mediat.1361-8(2018)

(±)8-HEPE is produced by non-enzymatic oxidation of EPA. It contains equal amounts of 8(S)-HEPE and 8(R)-HEPE. The ability of (±)8-HEPE to induce hatching of E. modestus and B. balanoides eggs is probably due to the presence of the 8(R) isomer within the racemic mixture.[1][2] Reference：[1]. Shing, T.K.M., Gibson, K.H., Wiley, J.R., et al. First total synthesis of a barnacle hatching factor 8(R)-hydroxy-eicosa-5(Z),9(E),11(Z)-pentaenoic acid. Tetrahedron Letters 35, 1067-1070 (1994).[2]. Hill, E.M., and Holland, D.L. Identification and egg hatching activity of monohydroxy fatty acid eicosanoids in the barnacle Balanus balanoides. Proceedings of the Royal Society of London Series B.Biological Sciences 247, 41-46 (1991).